1. Field of the Invention
This invention relates to arrangements for determining when the cash receptacle of a coin-operated device is filled to a predetermined level and more particularly to arrangements for signaling a central location when the fill in coin boxes of coin telephone stations reaches predetermined levels.
2. Description of the Prior Art
One of the most important maintenance problems associated with coin-operated devices that are placed in public locations is the scheduling of coin collections, since most common coin-operated devices contain a cash receptacle or coin box which is removed from the device and emptied periodically by a coin collector. The scheduling problem is particularly important to the telephone industry which maintains many coin-operated telephone stations, each requiring periodic collections. In the past, the usual way of determining when the coin boxes were to be emptied was to base collection intervals on extrapolations of previous records. However, it became apparent that such extrapolations were inaccurate and resulted in customer dissatisfaction because the coin boxes often became overfull and interfered with coin returns during the operation of the coin station. In addition, coin collectors were frequently dispatched to make a collection when a coin box was only partially full, resulting in a waste of time and money for the telephone company.
In an attempt to circumvent these problems, many signaling arrangements have been developed. One such arrangement utilized an oscillator at the coin telephone station. The oscillator was enabled by a mechanical probe which was pushed into operating position by an accumulating stack of coins in the coin box. When the coin stack reached a predetermined height, the oscillator was enabled. Subsequently, when a coin collect potential was received from a telephone central office, the oscillator operated to place a tone burst on the telephone line, which burst was received by a central location to indicate that a coin collection should be scheduled for the station.
One problem with the above oscillator arrangement is that the time length of the tone burst produced by the oscillator must be relatively long. The long tone burst is required by the operation of the coin station. During normal operation, the coin station line is disconnected from the central office when a coin collect potential is applied to the line. Thus, the tone oscillator associated with the coin fill detector must apply a tone signal to the station line until the line has been reconnected to the central office following the disconnection of the line upon application of the coin collect potential. The length of time during which the station is disconnected from the central office varies according to station location and the operation of the equipment at the central office. Therefore, the length of the tone burst required is relatively long to accommodate worst case conditions. Since the tone burst can be heard by the customer, it is often annoying and results in customer dissatisfaction.
Accordingly, it is one object of this invention to improve the efficiency of coin collection from coin-operated devices.
It is another object of the invention to signal a remote location that the cash receptacle in a coin-operated device is filled to a predetermined height.
It is a further object of the invention to control a signal generator located at the station so that a relatively short tone burst is required to inform a central location that a coin collection should be scheduled.